Foam producing composition containing whey solids

ABSTRACT

Highly economical agricultural foams were prepared from selected formulations containing whey solids, a surfactant and a viscosity builder. Greater versatility and durability are imparted to these foams by incorporating specified concentrations of animal hide glues. The foams are light in weight, of high expansion and form &#39;&#39;&#39;&#39;skins&#39;&#39;&#39;&#39; which make them specifically useful in providing protection to biological plants from frost and freezing temperatures; can be used as carriers for defoliants, herbicides, fungicides, sterilants and other chemicals; and, may be used as farm markers and foam covers after soil injection-fumigation.

United States Patent [191 Lam bou et al.

[ 1 June 24, 1975 [73] Assignee: The United States of America asrepresented by the Secretary of Agriculture, Washington, DC.

[22] Filed: Oct. 26, 1973 [211 Appl. No.: 410,052

[56] References Cited UNITED STATES PATENTS 12/1945Faulkner......................... 252/307 X l/l964 Gunther 252/307 X3,150,989 9/1964 Parsons 252/307 X 3,479,285 ll/l969 Barthauer 252/307 X3,712,865 l/l973 Evans et al. 252/356 X Primary ExaminerRichard D.Lovering Attorney, Agent, or FirmM. Howard Silverstein; Max D. Hensley[57] ABSTRACT Highly economical agricultural foams were prepared fromselected formulations containing whey solids, a surfactant and aviscosity builder. Greater versatility and durability are imparted tothese foams by incorporating specified concentrations of animal hideglues. The foams are light in weight, of high expansion and form skins"which make them specifically useful in providing protection tobiological plants from frost and freezing temperatures; can be used ascarriers for defoliants, herbicides, fungicides, sterilants and otherchemicals; and, may be used as farm markers and foam covers after soilinjection-fumigation.

7 Claims, No Drawings 1 FOAM PRODUCING COMPOSITION CONTAINING WHEYSOLIDS A non-exclusive, irrevocable, royaltyfree license in theinvention herein described, throughout the world for all purposes of theUnited States Government. with the power to grant sublicenses for suchpurposes. is hereby granted to the Government of the United States ofAmerica.

This invention relates to the solids recovered from whey remaining aftercheese is manufactured. More specifically, this invention relates to thepreparation of improved agricultural foams. The agricultural foams aredesigned to provide protection to biological plants in the form ofcarriers of chemicals that prevent infections of plants and contributeto improved methods of agriculture as an adjunct in weed eradication.

DEFINITIONS AND BACKGROUND Agricultural foams contain whey solidsderived from milk from which cheese is manufactured. Foams of thepresent invention are of whey solids origin. Whey solids are recoveredfrom whey, the aqueous solution remaining after the curds are collectedfor cheese manufacture. Whey solids, among other compounds, contain ahigh content of lactose ranging from 67 to 78.5 percent and proteinranging from 7.5 to 51 percent.

Materials from which the whey solids of this invention are obtainedoriginate with the dairy and cheese manufacturing industries. Wheysolids are available in a wide range of Trade Names reflectinggradations as to physical properties, prices, composition, and method ofmanufacture. Whey solids may be edible or inedible (feed-grade)depending on the method of manufacture. The majority of the edible wheysolids are spray dried leaving the protein content of the solidsessentially undenatured. inedible or feed-grade whey solids arepredominantly roller dried and the extent of denaturation of the proteinwould vary with the care exercised in drying the product. The wheysolids of the present invention were selected for preparation ofagricultural foams because they contain an appreciable content ofprotein in addition to the high lactose content.

B. H. Webb, USDA scientist, described the Utilization of Whey in Foodsand Feeds in the proceedings of the Whey Utilization Conference,University of Maryland, June 1970. From this report we learn that theprotein present in whey solids in lactalbumin and the milk sugar islactose. If during recovery the lactose is crystallized, the product isstabilized and does not readily pick up moisture and cake. Likewise, ifthe whey solids are manufactured by foam-spray drying, the sphericalparticles will be readily dispersible and will not cake. The leastexpensive of the whey solids products are those that are roller driedand are suitable only for animal feed.

These agricultural foams contain glues derived from collagen which is aprotein constituent of animal hide and bone. Foams of the presentinvention are of whey solids origin to which selected concentrations ofhide glues are added to improve the desired characteristics. Hide gluesare derived from collagenous materials present in hide pieces and inconnective tissue associated with the hide. Collagen contains adisproportionately high content of hydroxyproline and proline,respectively 14 percent and 15 percent.

The glues of this invention originate with the packing and canningindustries and are principally of cattle origin. As a group, hide gluesare the strongest most versatile of animal glues with respect to broadusage in industry. The glues of the present invention were selected forpreparation of the foams of this invention because they are basicallyprotein.

The National Association of Glue Manufacturers. Inc., with headquartersin New York City, has prepared a booklet bearing the title Animal Gluein Industry" describing an excellent overall view on glues. From thispiece of literature we learn that "Animal glue is an organic colloid ofprotein derivation which meets with constantly increasing acceptance foradhesive, sizing and coating compositions, and colloidal applications inindustry. This product is the oldest type of glue Skin is a term usedwith reference to the agricultural foams of this invention in describingthe outermost layer and is usually a continuous filament-type layerwhich forms on top the wet foam within 1 to 4 hours after the foam hasbeen allowed to set. This skin protects the foam underneath from theravages of wind and seals the area from rapid changes in temperature.The skin helps keep the foam where it has been placed, that is, withoutdissipation by the elements; For purposes of this invention the concernhas been in securing the foam to the location where it is installed,around and about a botanical environment where filaments similar to aspider web anchor skin to blades of grass, stems, leaves, or otherprotrusions about the periphery of the earth. The skins of our foamshave thicknesses ranging from 0.0001 to 0.001 inch.

These agricultural foams contain viscosity builders that are complexpolysaccharides such as Xanthan gum (molecular weight about 6,000,000)which is manufactured commercially as the sodium, potassium or calciumsalt containing D-glucose, D-mannose and D- glucuronic acid as thedominant hexose units in a ratio of 3:3:1 and low percentages (under 5percent) of O- acetyl groups and pyruvic acid groups. Food grade Xanthangum known as Keltrol, an industrial grade, Kelzan, and mixtures ofKelzan and locust bean gum, a galactomannan polysaccharide (molecularweight about 310,000) have been used. The latter mixture is knowncommercially as Kelgum. Other viscosity builders, also polymers, arehydroxyethylcellulose and hydroxypropyl cellulose.

Surfactants used in these foams may be selected from a group such as ananionic ammonium lauryl trioxyethylene sulfate or one of the ammoniumsubstituted alkyl sulfates wherein the alkyl component ranges from C12to C15.

THE PRIOR ART US. Pat. No. 2,875,555, issued Mar. 3, 1959, discloses theuse of foam in protecting plants from frost damage to yield a botanicalplant which would be free from frostation and would comprise covering atleast the susceptible portion of said plant when danger of frost wouldbe iminent, with an enveloping protective layer having the thickness ofat least about A inch of a stable, Ionglasting foam. These inventorsdisclose having covered a plant to the extent of 1 inch thickness withfoam which would last at least 4 hours. According to the process of saidinvention, it is possible to produce a foam which will live overnight.The volume of foam produced by their process would be ten times as greatas the formulation from which it was produced.

Polymer-forming materials were included in their formulations.

Comparatively, it should be noted that the volume of the foam of thepresent invention is kept at between 1 l and 70 times as great as theformulation from which it originated. Persistence or life-expectanciesof these foams depended on the temperatures at which the foams were usedand ranged from 0.8 to 3 at 90F; 7 to 24 hours at 75F and 2 to 8 days at36F (Table B).

The whey solids of the present invention contain protein which is apolymer and lactose, a dimer; animal glue is a polymer; and theviscosity-builder is a polymer. No saponin is employed. The saponin usedby others corresponds to our surfactants, selected for their highfoaming qualities. The polymeric materials employed by the prior artcorresponds to our whey solids, animal glue and viscosity-builder. Thequantities which have led to our preferred embodiments indicateformulations which would contain about 1 to 2 percent whey solids, 0.5to 1 percent animal glue, 0.3 percent to 2 percent surfactant and 0.1 to0.3 percent of a viscositybuilder, which is also a polymer.

In the prior art also we find an article by Paul A. Sanders whichappears in Vol. 84 of the October 1969 issue of American Perfumer andCosmetics under the title Unusual Aqueous Aerosol Foams. The compositionand properties of these foams have different uses than those of theagricultural foams of the present invention, which were prepared at theSouthern Regional Research Center in New Orleans. Sanders foams areprincipally for use as cosmetics and in pharmaceutical products, and arecharacterized as snowflake foam," crackling foam, collapsing foam,buoyancy foam," etc. Such materials would not be suitable foragricultural foams.

OBJECTIVES OF THE PRESENT INVENTION The main object of the presentinvention is to provide a foam producing agent in the form of awaterdispersible proteinaceous-carbohydrate product.

A secondary objective is to increase the effectiveness of the foamingagent derived from milk (whey solids) by incorporating therein one ormore protein bearing materials.

Other objectives of the present invention are to provide cold weatherfoams for protecting botanical plants from frost and freeze damage; toprovide foams for use as carriers for herbicides, defoliants, nutrientsor other agricultural chemicals; and to provide farmers with aself-destructive foam maker with a life expectancy of at least twohours.

In the investigative work leading to the present invention,effectiveness of feed-grade whey solids can be improved considerablybeyond that already reported (Ser. No. 374,731, filed June 28, 1973) bythe addition of 0.5 to 1.0 percent animal glue. Expansions (foam volumevs liquid volume) obtained ranged from 25 to 51 times that of theoriginal liquid volume. Persistence at 36 F ranged from 32 to 68 hoursand at 64 to 78F from 3 to 27 hours, depending on the concentration ofanimal glue added. Quality of persistence could be further tailored forthe particular end use by varying the concentrations of ingredients asfollows: 1 percent whey solids plus 2 percent surfactant, plus 1 percentanimal glue and 0.3 percent of a viscosity-builder improved persistenceof the foams by 200 percent at 36 F, 385 percent at 68F, and 400 percentat 73F; when the concentration of the surfactant was reduced to 0.3percent, greatest persistence, 192 hours or 8 days at 36F, was obtained;skins were also strongest when the concentration of surfactant was heldat the 0.3 percent level; if weaker skins and less persistence aredesirable, an increase in concentration of surfactant would provide thenecessary qualities; dilution with water of the above formulation to theextent of 20 percent, that is, increasing the volume of the formulationby 20 percent, seemed to maximize foam characteristics of a good,all-purpose formulation.

In the process of investigation, the combination of whey solids andanimal glue was selected because agricultural foams are generallywater-based, selfdestructive, and can be made with varying lifetimeperiods. Agricultural foams can be made from nontoxic ingredients suchas whey solids and animal glues and can be formulated to endure fordifferent periods of time and weather conditions depending on theapplication for which they are designed. Of immediate concern isprotection of biological plants from frost and freeze damage, and therequirements would indicate that the life span of the foam, or of theduration of protection, would be about 24 to 48 hours or longerdepending on the geographical area where the plants are to be protected.Proper adjustment of concentrations of ingredients of the aboveformulation will produce as much as 192 hours or 8 days of protectionnear, at, or below freezing temperatures. On the other hand,formulations investigated were amenable to adjustments for use ascarriers for herbicides, fungicides, defoliants and the like where lifeexpectancy of a foam is short, perhaps one to three hours. Service as asoil cover after injection of the soil with volatile chemicals,requiring a lifeexpectancy of three to 5 hours was also possible. Thepresent invention provides the farmer who is working a farm ofapproximately two miles square with a means of marking his startingplace and outlining the area he has worked. Life-span of such a foamwould be perhaps at least two hours.

THE PROBLEM Investigative work conducted by Louisiana State Universityin the year 1967 indicate that foams having a use-life of 24 to 48 hoursunder freezing weather conditions were obtained when edible gelatin wasused as the stabilizer; however, this stabilizer is unsuitable forlarge-scale crop protection mainly because of the costs of ingredientsand manner of application. For practical applications it was necessaryto develop formulations and reduce costs to the lowest possible levelwhile maintaining all other requirements for the foams. The requirementsfor such foams included low cost, easy generation, zero toxicity (forboth plants and animals), sufficient stability to maintain an adequatecover overnight in freezing temperatures and to dissipate with risingtemperatures. The combined requirements called for foams with insulativecapacities which would allow them to serve as protective covers underadverse weather conditions when winds are high and temperatures drop to,or below freezing.

Preferred spumific formulations are products of investigative effort.These formulations contain specified quantities of whey solids andanimal glues which are most suitable. The most suitable whey solids arethe subject of an earlier patent application (Serial number not receivedyet), as are the animal glues (Ser. No.

203,836, filed Dec. 1, 1971, and now abandoned). Formulations wereevaluated for drainage, density. expansion. viscosity and persistence orlife-span. Techniques employed were those of Brand and Chesness in theirPhysical Properties of Foam Insulation for Protecting Plants AgainstCold Weather," a paper presented at the Winter Meeting of the AmericanSociety of Agricultural Engineers in Chicago, Illinois, Dec. -13, I968.The laboratory-size cone-type foam generator fabricated by Brand andChesness, was used to generate selected foams for evaluation.

The generated foams were observed at room temperature (about 75F), at36F and outdoors where the temperature varied widely. Not only doestemperature vary widely, but other conditions such as wind speeds, andcloudy vs. full sun exert their influence. Hence persistence outdoorstends to vary as shown in Table A.

The drained liquor was collected in the most suitable graduatedcylinders (I00 ml). Drainage was measured (in ml) as quantity of liquorcollected from collapsing foam with respect to time, that is, volume vs.time." Persistence was observed as the period of time required for afoam to retain 33 percent of its original depth. Density and Expansionwere calculated from the weight and volume of the foam.

IMPROVEMENT USING ANIMAL GLUES We have discovered that whey solidscombined with TABLE A IMPROVEMENT OF WHEY SOLIDS FOAM CHARACTERISTICSWITH ADDITION OF PROTEIN AS ANIMAL GLUE Concentration Whey Animal SolidsGlue Expan- Persistence in Hours at sion 36 73F 64-78F l SIX 32 6 7 l0.5 38X 415 6 23 l 0.8 3 IX 60 I8 3 l l 3 IX 66.5 24 27 2 50X 41 6 7 20.5 45X 56 8+ 8 2 0.8 33X 56 I7 8 2 l 25X 68 24 Variable outdoortemperatures.

Table B EXAMPLES OF FOAM FORMULATIONS IMPROVED BY ADDITION OF ANIMALGLUE- THEIR PERSISTENCE AND APPLICATION.

T Composition of Formulation Whey Animal Viscosity Surfactant SurfactantSkin Expan- Hrs. Persistence at Solids Glue Builder A B Fom'iation sion36F 75F 90F Application 1 ,5 0.5 None 70X 0.8 Short term foam 0.8 .80.24 0.7 Good 36X I 7 30 Good allpurpose foam l.0 |.0 0.3 0.3 Excel- 20XI92 8 LS For use at/or below lent freezing L0 1.0 0.] 2.0 Good X 72 92.0 All-purpose l.0 L0 0.2 2.0 Good 28X I44 lb 2.5 For use at/or belowfreezing L0 l.0 0.3 2.0 Good 2lX I20 17 l.0 L0 0.5 2.0 Good 1 IX 108 24L0 l.0 0.3 l.l Good 37X 70 8 1,5 All-purpose L0 l.0 0.3 L5 Good 43X 85 7L3 1.0 L0 0.3 1.9 Good 43X 53 7 L3 animal glues are greatly improvedstabilizers in formulations used to generate foams for insulatingplants, as herbicide, fungicide and defoliant carriers, as farm markersand as covers over soil after injection of the soil with a gaseousfumigant. Persistence of the foams was enhanced by choice andconcentration of surfactant and choice and concentration of aviscositybuilder. Costs of the formulations could be reduced up to 90percent depending on the ingredients included and their concentrations.

The following examples are provided to illustrate the invention,utilizing the preferred embodiments, and are not to be construed aslimiting the invention in any manner whatever.

EXAMPLES Improvement in whey solids foam characteristics by addition ofanimal glue protein is outlined in Table A.

The following conclusions may be drawn from Table B. Foam formulationsmay be tailored from whey solids for a variety of applications. Mixedwith animal glue, a viscosity-builder and a surfactant, a goodall-purpose foam is obtained when the 1 percent whey solids, l percentanimal glue, 0.3 percent viscosity-builder and 1 percent surfactant isdiluted 20 percent. If the foam is to be used at or near freezingtemperatures, concentrations of whey solids and animal glue should be atthe I level, there should be no change in the concentration ofviscosity-builder, but the concentration of surfactant should be reducedto 0.3 percent. This produces a dense, low expansion foam which enduresat 36F for 192 hours or 8 days.

We claim:

1. A foam precursor composition that can be generated to a foam capableof retaining its configuration at or below 36F for a period of time upto about 8 days, said foam precursor composition consisting of ahomogenous suspension of water containing about from I to 2 percent ofwhey solids, the protein content of which is about from 7.5 to 51percent; about from 0.5 to 1 percent of animal hide glue, a collagenouscompo- 7 8 nent; about from 0.3 to 2 percent of a surfactant se- 3. Thefoam precursor composition of claim 1 lected from the group consistingof: wherein the surfactant is an ammonium substituted C an anionicammonium lauryl trioxyethylene to C lk |f r Sulfate f 4. The foamprecursor composition of claim I ammomum Subsmuted C12 to CM islflfateiand 5 wherein the viscosity builder is hydroxyethyl cellulose.about from 0.1 to 0.3 percent ofa vlscosity builder 5' The foamprecursor composition of claim I sdficted i the group of waterd'spersble poly wherein the viscosity builder is hydroxypropyl cellumersconsisting of: lose hydroxyethylcenulose' 6. The foam precursorcomposition of claim I hydroxypropyl cellulose,

xanthan gum, both food grade and industrial wherein the viscositybuilder ls either food grade or ingrade and dustnal grade xanthan gum.

mixtures of industrial grade xanthan gum and The foam N composltlon ofClaim 1 locust b gurrr wherein the viscosity builder is one ofa varietyof mix- 2, Th f precursor composition f l i 1 l5 tures of industrialgrade xanthan gum and locust bean wherein the surfactant is an anionicammonium lauryl gum.

trioxyethylene sulfate.

1. A FOAM PRECURSOR COMPOSITION THAT CAN BE GENERATED TO A FOAM CAPABLEOF RETAINING ITS CONFIGURATION AT OR BELOW 36**F FOR A PERIOD OF TIME UPTO ABOUT 8 DAYS, SAID FOAM PRECURSOR COMPOSITION CONSISTING OF AHOMOGENOUS SUSPENSION OF WATER CONTAINING ABOUT FROM 1 TO 2 PERCENT OFWHEY SOLIDS, THE PROTEIN CONTENT OF WHICH IS ABOUT FROM 7.5 TO 51PERCENT; ABOUT FROM 0.5 TO 1 PERCENT OF ANIMAL HIDE GLUE, A COLLAGENOUSCOMPONENT; ABOUT FROM 0.3 TO 2 PERCENT OF A SURFACTANT SELECTED FROM THEGROUP CONSISTING OF: AN ANIONIC AMMONIUM LAURYL TRIOXYETHYLENE SULFATE,AND AN AMMONIUM SUBSTITUTED C12 TO C18 ALKYL SULFATE; AND ABOUT FROM 0.1TO 0.3 PERCENT OF A VISCOSITY BUILDER SELECTED FROM THE GROUP OF WATERDISPERSIBLE POLYMERS CONSISTING OF: HYDROXYETHYL CELLULOSE,HYDROXYPROPYL CELLULOSE, XANTHAN GUM, BOTH FOOD GRADE AND INDUSTRIALGRADE, AND MIXTURES OF INDUSTRIAL GRADE XANTHAN GUM AND LOCUST BEAN GUM.2. The foam precursor composition of claim 1 wherein the surfactant isan anionic ammonium lauryl trioxyethylene sulfate.
 3. The foam precursorcomposition of claim 1 wherein the surfactant is an ammonium substitutedC12 to C18 alkyl sulfate.
 4. The foam precursor composition of claim 1wherein the viscosity builder is hydroxyethyl cellulose.
 5. The foamprecursor composition of claim 1 wherein the viscosity builder ishydroxypropyl cellulose.
 6. The foam precursor composition of claim 1wherein the viscosity builder is either food grade or industrial gradexanthan gum.
 7. The foam precursor composition of claim 1 wherein theviscosity builder is one of a variety of mixtures of industrial gradexanthan gum and locust bean gum.